The printed quality of high-resolution image data can suffer when printed with relatively low-resolution printing devices. For example, when an image is printed for a relatively low resolution newspaper, book, or magazine, such printing devices often clump the ink or toner pixels into clusters (dots) at an edge. Screening of high-resolution image data has been employed to reduce its pixel depth and to cluster the “on” pixels into dots. In such applications, halftone screens reproduce solid, smooth, or slowly changing regions of the image data well, but may render printed edges (and other discontinuous regions) as fuzzy or jagged structures. Clustered dot halftone dots usually have between 4×4 and 10×10 output pixels per halftone dot. In other words the resolution of the dots is much less than the basic output resolution. This lower resolution is very visible at edges. In contrast, error diffusion screens or threshold screens render edges sharp and well defined in part because these screens generates edges at the higher output pixel resolution.
Half tone screening of image data is employed to reduce the pixel bit depth of digital image data. For instance, a halftone screen may be applied to simulate continuous tones in an image that is represented with screened image data that includes pixels of a bit depth of a single bit. In some halftone images, a pixel's single bit is either completely on or completely off. Dots of various amplitudes and frequencies may be clustered, via pixels of a 1-bit pixel depth, to render certain features in the screened image data. Such halftone screens are often applied when printing images for books, magazines, newspapers and the like. However, details of image data that are represented by screened image data are often lost due to lower cluster dot resolution than output pixel resolution. Thus, it is with respect to these considerations and others that the following disclosure is provided.